Electromagnetism

Question 1

State Lenz’s law

Answer 1

The direction of induced emf or current is always oppsoing the change producing it
due to conservation of energy

Question 2

Explain how a velocity selector

Answer 2

A device that uses e and b fields to select charged particles of specific velocity

• charged particles travelling at different speeds pass through a slit containing the two fields
• the fields deflect them in opposite directions
• only particles travelling at specific speeds will cancel out the deflection and pass through a second slit

Question 3

How can transformers be made more efficient?

Answer 3

-using low resistance windings to decrease power losses from heating due to current

Question 4

Define magnetic flux

Answer 4

-using low resistance windings to decrease power losses from heating due to current